[MauranKilom]

std::dequeue is as good as useless. The defaults for "batch size" in different compilers are at extreme opposites of the tradeoff spectrum. So unless you really don't care about performance, memory or portability, it's not a datastructure you can rely on.

From memory:

In MSVC, dequeue will allocate memory for every single element if your elements are > 8 bytes. This will never be changed, due to ABI compatibility.

Clang and gcc have batching sizes of 1K and 4K (i.e. you throw out a whole page of memory even if your dequeue contains only 1 element).

[owl57]

I had a vague feeling that std::deque is a "heavy" thing which you shouldn't have a million of, but iterating through a couple big ones is pretty fast. 1–4K batches wouldn't hurt my feelings. Looked up GCC, it's actually slightly less heavy at 512 bytes per node[1]. But the MSVC part — that caught me completely off guard.

https://github.com/gcc-mirror/gcc/blob/47749c43acb460ac8f410...

[jcelerier]

In general it's better to use the same standard library everywhere - discrepancies like that occur for almost every type so if you care about having the same performance on every platform... Either use libc++ or boost

[gpderetta]

IIRC boost.containers has a standard conforming deque with configurable batch size.